From patchwork Sun Jul 3 15:06:42 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Feiran Zheng X-Patchwork-Id: 103014 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [140.186.70.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 1821DB6F64 for ; Mon, 4 Jul 2011 01:14:25 +1000 (EST) Received: from localhost ([::1]:44231 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QdONJ-0005sU-3D for incoming@patchwork.ozlabs.org; Sun, 03 Jul 2011 11:14:21 -0400 Received: from eggs.gnu.org ([140.186.70.92]:59277) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QdOH3-0004pb-2g for qemu-devel@nongnu.org; Sun, 03 Jul 2011 11:07:54 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1QdOH1-0004qm-6Q for qemu-devel@nongnu.org; Sun, 03 Jul 2011 11:07:52 -0400 Received: from mail-iw0-f173.google.com ([209.85.214.173]:46065) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QdOH0-0004qh-So for qemu-devel@nongnu.org; Sun, 03 Jul 2011 11:07:51 -0400 Received: by iwn3 with SMTP id 3so4509959iwn.4 for ; Sun, 03 Jul 2011 08:07:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=from:to:cc:subject:date:message-id:x-mailer:in-reply-to:references; bh=nZOmmWexEhmDsne6bmFbx4WzSdsWcg9Edaf5/bGIYeA=; b=Vs64wuy1yryNqwmULL+N/AO0+MZVkqe9t+HHTx6Hpq+eP+OqW3YpiB8Rg7/Bwa/nkl 3DnqcXZAEwoYBMdPCAggvDWDJAud+the5usubtA4lSeHndY3w57HR58J5lX/EmPGvg2/ 7uZYRYQhoO7F0pu2Erb2JiNBj2kGFWep2Ktvk= Received: by 10.42.74.195 with SMTP id x3mr5586306icj.277.1309705670178; Sun, 03 Jul 2011 08:07:50 -0700 (PDT) Received: from localhost.localdomain ([111.187.70.55]) by mx.google.com with ESMTPS id d6sm5419466icx.13.2011.07.03.08.07.47 (version=TLSv1/SSLv3 cipher=OTHER); Sun, 03 Jul 2011 08:07:49 -0700 (PDT) From: Fam Zheng To: qemu-devel@nongnu.org Date: Sun, 3 Jul 2011 23:06:42 +0800 Message-Id: <1309705612-27079-3-git-send-email-famcool@gmail.com> X-Mailer: git-send-email 1.7.6 In-Reply-To: <1309705612-27079-1-git-send-email-famcool@gmail.com> References: <1309705612-27079-1-git-send-email-famcool@gmail.com> X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6 (newer, 2) X-Received-From: 209.85.214.173 Cc: kwolf@redhat.com, Fam Zheng , hch@lst.de, stefanha@gmail.com Subject: [Qemu-devel] [PATCH v7 02/12] VMDK: bugfix, align offset to cluster in get_whole_cluster X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org In get_whole_cluster, the offset is not aligned to cluster when reading from backing_hd. When the first write to child is not at the cluster boundary, wrong address data from parent is copied to child. Signed-off-by: Fam Zheng --- block/vmdk.c | 8 +++++--- 1 files changed, 5 insertions(+), 3 deletions(-) diff --git a/block/vmdk.c b/block/vmdk.c index 3b78583..03a4619 100644 --- a/block/vmdk.c +++ b/block/vmdk.c @@ -514,21 +514,23 @@ static int get_whole_cluster(BlockDriverState *bs, /* 128 sectors * 512 bytes each = grain size 64KB */ uint8_t whole_grain[extent->cluster_sectors * 512]; - // we will be here if it's first write on non-exist grain(cluster). - // try to read from parent image, if exist + /* we will be here if it's first write on non-exist grain(cluster). + * try to read from parent image, if exist */ if (bs->backing_hd) { int ret; if (!vmdk_is_cid_valid(bs)) return -1; + /* floor offset to cluster */ + offset -= offset % (extent->cluster_sectors * 512); ret = bdrv_read(bs->backing_hd, offset >> 9, whole_grain, extent->cluster_sectors); if (ret < 0) { return -1; } - //Write grain only into the active image + /* Write grain only into the active image */ ret = bdrv_write(extent->file, cluster_offset, whole_grain, extent->cluster_sectors); if (ret < 0) {